The patent was filed in 2010 at a time when many tech firms made grabs for all kinds of technological innovations.

IBM said that it would "dedicate the patent to the public".

It has led to accusations that the US Patent Office (USPTO) is out of touch.

In a statement, the IBM said that it had notified "the USPTO that it foregoes its rights to the patent. As a result, the patent is released into the public domain".

Holiday postcard

The described patent included details such as how a user needed to input "availability such as a start date, an end date and at least one availability indicator message".

The only feature of the system that differs from existing out-of-office systems is one that automatically notifies people a few days before the person goes on holiday so that they can prepare for a colleague's absence, according to EFF.

It likened this change to "asking for a patent on the idea of sending a postcard, not from a vacation, but to let someone know you will go on a vacation".

It also criticised the US Patent Office for granting such a patent.

"It never considered any of the many, many existing real-world systems that pre-dated IBM's application," it writes.

Patent bonanza

There has been widespread criticism of patents being granted for abstract ideas rather than for brand new technical advances.

Chris Price, a UK and European patent lawyer at law firm EIP, said of the time taken to grant the patent: "Seven years does seem a little bit on the long side but it is by no means unusual for it to take that long to grant patents."

He added: "In Europe, patents are granted for inventions that solve technical problems and if they are seen to address something that is business-related or an administrative process they are not given. In the US the situation is historically more permissive."

Earlier this year IBM announced that it had broken the US patent record with more than 8,000 patents granted to its inventors in 2016. This marks the 24th consecutive year that it has won the title.

Its patent output covers a diverse range of inventions, including breakthroughs in artificial intelligence, cognitive computers and cybersecurity.